Fuel supply system



Sept 27 1949- E. o. wlR-rH Erm. 2,482,956

FUEL SUPPLY SYSTEM v Filed Aug. 1o, 1946 :sv sheets-sheet 1 YWZ@/rToRA/er.

' Sept. 27, 1949.

Filed Aug. 10, 1946 t. o. wlRTH ErAL FUEL SUPPLY SYSTEM 3 Sheets-Sheet 2Sept. 27, 1949.

Filed Aug. 10, 1946 E. O. WIRTH ETAL FUEL SUPPLY SYSTEM 3 Sheets-Sheet 3f Patented Sept. 27, 1949 I' UNITED STATES `PATENT oFFlcE FUEL SUPPLYSYSTEM Emil 0. Wirth and Frederik Barfod, South Bend, Ind., assignors toBendix Aviation Corporation, South Bend, Ind., a corporation ofDelaware` Application August 10, A1946, Serial No. 689,711

The present invention relates to a fuel system and more particularly toa fuel supply system for internal combustion engines wherein the fuel issupplied under superatmospheric pressure.

An object of the present invention is to provide a fuel supply system ofthe pressure feed'type wherein the ratio of fuel-to-air is controlled inaccordance with certain engine operating variables.

Another object of the invention is to provide a fuel supply system foran internal combustion engine or the like in which the ratio offuelto-air is controlled in response to the same engine operatingvariables that control the quantity of air entering the engine.

Another object of the invention is to provide a fuel supply system foran internal combustion engine in which ,a controlled supply of fuel tothe engine is obtained by regulating the effective fuel metering headacross a metering orifice in accordance with speed and temperature ofthe engine and pressure of the air in the induction passage or intakemanifold thereof.

Still another object ofthe present invention is to provide a fuel supplysystem for an internal combustion engine capable of distributing thefuel uniformly to several cylinders of the engine under all normalengine operating conditions.

Still another object is to provide a fuel supply system for supplyingfuel at superatmospheric pressure in accordance with engine speed andtemperature and intake manifold pressure Wherein a device is included toprovide temporary fuelto-air enrichment during acceleration of theengine.

Another object is to provide in a fuel supply system of the aforesaidtype a means for correcting the fuel-to-air ratio in accordance withvariations in volumetric efficiency of the engine.

Another object is to provide a compact, accurate fuel supply andmetering device for delivering fuel to the engine in accordance withcertain engine variables.

In order to obtain, the foregoing objects and other objects which willbe apparent from the following description, the present inventionincludes, yin a fuel supply system of an internal combustion engine, aVcentrifugal pump driven at a speed directly proportional to the speed ofthe varies in accordance with the square of the engine speed, and a fuelmetering control unit having a regulating valve actuated in response tothe pressure in the induction passage orintake manifold for controllingthe fuel-to-air ratio relative 26 Claims. (Cl. 12S-119) to saidpressure. A fuel distributor preferably formed integrally with theimpeller of the aforementioned centrifugal pump is included to supplyfuel to a plurality of discharge nozzles disposed in the intakemanifold, the discharge of fuel through the several nozzles beingsynchronized with the firing of the various cylinders adjacent v engineto provide a fuell metering head which thereto. To provide for certainspecial operating conditions the fuel supply system also includes adevice for giving temporary enrichment to the mixture when the throttlevalve is opened, and a mechanism having a temperature responsive elementincorporated therein for enriching the fuelto-air mixture while theengine is cold.

From the detailed descriptionr which follows, modications of andadditions to the present invention will be apparent to those skilled inthe art. It is to be understood that although only the preferredembodiment of the invention is disclosed in detail, many variationsemploying the principles of the invention are possible, and wecontemplate the use of any such variations in structure, arrangement andmode of operation that properly fall within the scope of the appendedclaims.. o

Figure 1 ofthe drawings is a diagrammatic view of the present fuelsystem showing in cross section the various elements comprising thesystem and their position in relation to each other therein;

Figure 2 is a plan view of a fuel distributor showing the various fueldischarge conduits disposed in the marginal area of the distributorcover and a fuel inlet conduit leading to the center thereof;

Figure 3 is an enlarged view of the throttle control mechanism shown inFigure 1;

Figure 4 is a cross section through a discharge nozzle and a portion ofthe intake manifold taken on line 4 4 of Figure l; and

Figure 5 is a diagrammatic view of a modification of the present fuelsystem.

Referring to Figure 1 of the drawings, in which various elements areshown diagrammatically the present charge forming system broadlyconsists of a fuel metering device 2, an induction passage 4 havingdisposed therein a throttle valve 6 and an automatic choke and fast idlearrangement generally showing at 8. The expression induction passage asused throughout the specification and in the appended claims embracesany o'r all air intake passageways leading to the engine, as forexample, the intake manifold and the passageway in which a throttlevalve is dis- In Figure 1, a gear pump shown generally at I is providedfor delivering fuel to a metering unit at a substantially constantpressure, in which pump gear |2 is mounted on shaft |4 and meshes withgear |6 mounted on shaft |8, said gears being driven by the engine, notshown, through any suitable and well known coupling` means oonnected tothe free end of shaft I4. Any other type of pump may be used in place ofthe gear pump; however, the gear pump is especially suitable for thefuel delivery means in the present metering device. A fuel inlet 20 andpassage 2| introduce the fuel into the vfuel supply system and to pump|0 where it is carried by the meshing gears I2 and- I6 around theperiphery of chamber 22 and discharged into pump outlet passage 24. Avalve regulated pump bypass 26 communicating with outlet passage 24 andinlet passage 20 is provided to maintain the fuel supply at asubstantially constant pressure. The valve which regulates the pumpby-pass, generally shown at 28, consists of a beveled disc 29 adapted toclose orifice 30, a valve stem 32 slidably mounted in valve guide 33,and a calibrated spring 34 adapted to react between disc 29 and a cap 35to urge the valve towards its closed position.

Pump I0 delivers fuel through a passage 24 to a, centrifugal pump,generally shown at 36, consisting of an impeller 38 having blades 39mounted on one end of the aforementioned gear pump shaft |8 and adaptedto rotate therewith, and a spiral annular passage 40 around theimpeller, said spiral passage communicating with conduit 42. The fuelwhich is discharged from the impeller 38 is delivered to chamber 44 ofthe pressure regulating `unit 45 through a metering jet or orifice 46disposed in conduit 42. The fuel pressure in chamber 44 is controlled bypoppet valve 48 mounted on a valve stem 50 which is secured to aflexible diaphragm 52 and spring retainers 54 and 55 by pin 56 insertedin the end of stem 50. The diaphragm 52 which forms one wall of chamber44 is secured in place by being marginally clamped between casings' 58and 59 of the pressure control unit.

A conduit 60 carries the fuel discharged from the metering unit throughorifice 41 to a distributor, shown generally at 62, disposed in thelower side hof the centrifugal pump and preferably formed integrallytherewith. The distributor as well as the pump is driven by shaft 8. Therotor for distributing the fuel from intake conduit 60 to a plurality ofdischarge conduits 66 -contains a radial groove 61 communicating withintake conduit 60 and intermittently withthe several discharge conduits66 as the rotor is driven by shaft |8. The fuel discharge conduitscommunieating with the distributor are provided with nozzles 68 sodisposed in the intake manifold 10 as to provide maximum fueldistribution in the air entering the cylinders adjacent the severalnozzles. Each nozzle is adapted to supply fuel to two adjacent cylindersand is connected with two alternately disposed outlet ports in thedistributor cover as shown in Figures 1 and 2, to provide charges offuel to two cylinders in timed relation with the cycle of the respectivecylinders.

The valve 48 which controls the effective size of orifice 41 maintainsthe pressure in chamber 44 substantially equal to the pressure inchamber 12 situated in the pressure control unit 45 with the side ofdiaphragm 52 opposite. chamber 44 comprising one wall of said chamber12. A spring 14v provided in chamber 44 and adapted to react betweenspring retainer 55 and one wall of said '4 chamber,and a spring 16provided in chamber 12 and adapted to react between spring retainers 54and 11 are so calibrated as to close valve 43 when the engine is notrunning, thereby preventing the discharge of fuel through orifice 41 andconduit 60 to the engine. It is to be noted that the spring retainersare so disposed on opposite sides of the diaphragm 52 as to comprisestiifening members therefor and that the peripheral edge portions areturned outwardly relative to said diaphragm, both to prevent theirdamaging the diaphragm in any way and to retain the springs in theirproper positions. A means may be provided such as screw 18, formodifying the tension in springs 14 and 16, thereby modifying thepressure of fuel discharged through valve 48 and consequently the amountof said fuel.

The pressure in chambers 44 and 12 is determined by the pressure incontrol passage which communicates with the unmetered fuel posterior tothe impeller 38 and with fuel anterior to the impeller through orifice82. A pressure responsive poppet valve 84 controlling orifice 86 isprovided for regulating the pressure in control passage 80, theeffective size of said orice being regulated in accordance with thepressure in the induction passage acting on diaphragm 81 in oppositionto a spring 88 tending to close the valve. Valve 84 is supported byvalve stem 89 slidably received in valve guide 90 and secured todiaphragm 9| and stiffening members 92 and 93 by pin 94 seated in theend of stern 89. Diaphragm 9| is secured in place by being marginallyclamped lbetween the body of the regulator unit and a spacer ring 95 anddiaphragm 81 between said spacer ring and casing 96, thus formingchamber 91 for the unmetered fuel posterior to the impeller, chamber 98vented'to the atmosphere for air at barometric pressure and chamber 99communicating with the induction passage through conduit |00 for air atthe pressure in said induction passage. Stiffening members |0| and |02are secured to either side of diaphragm 81 by a rivet inserted incentrally located holes in said members and diaphragm. Stiffening member|02 serves as a spring retainer for calibrated spring 88 disposed inchamber 99 and adapted to react between said spring retainer and asecond spring retainer |03 mounted on the end of screw |04. The twodiaphragms are held in fixed relationship to one another, and, as shownin the drawings, diaphragm 9| is substantially smaller than diaphragm81. The size of diaphragm 9| is selected relative to the size ofdiaphragm 81 such that the pressure of the unmetered fuel urgingdiaphragm 9| and valve 84 to the left will best correct the rate of fuelsupply to compensate for variations in volumetric efficiency, as will bemore fully explained hereinafter.

An accelerating mechanism generally shown at |05 communicating directlywith conduit 60 leading to distributor 62 is included in the fuel systemto provide temporary enrichment of the fuelto-air mixture when thethrottle valve is opened. This enriching mechanism consists of anorifice |06 controlled by poppet valve |08 formed integrally with valvestem ||0 which is slidably received in valve guide and secured toflexible diaphragm ||2 and stiffening -members ||4 by a pin I6 seated inthe end of stem 0. Diaphragm I2 and a somewhat larger diaphragm ||8 heldin spaced relation thereto form chamber |20 which communicates with theinduction passage through conduit |00 to open valve |08 when thepressure in said induction passage is suddenly increased. Anotherchamber |22 is provided behind diaphragm ||8 and communicates with theinduction passage through a restricted port |24 and conduit |00. Port|24 permits the gradualv equalization of pressure on either side ofdiaphragm IIB, thereby permitting the seating of valve |08 over orifice|06. A chamber |26 on the side of diaphragm ||2 opposite-chamber'l20communicates with orifice |06 and with passage 42 for the unmetered fuelposterior to the impeller., A. spring |28 disposed in chamber |22 reactsbetween spring retainer |29 and one wall of said chamber in oppositionto the pressure in chambers |20 and |26 to urge poppet valve |08 to aposition restricting the flow of fuel through orifice |06 and to passage60. It may be seen that upon opening movement. of the throttle, theresulting increase in pressure in the induction passage and in conduit|00 and chamber |20 .will y exert a greater total force on the largediaphragm ||8 than on-the small diaphragm I2, tending to compress spring|28 and to relieve to some degree the pressure urging poppet valve |08to its closed position. The pressure Aof the unmetered fuel acting ondiaphragm I I2 urges said diaphragm in the direction required toopen'poppet valve |08, thus permitting a temporary increase in thedischarge of fuel through orifice |06, conduit 60, and distributor 62into the intake manifold 10.

The present invention includes an automatic mechanism for enriching thefuel-to-air mixture under abnormal engine operating conditions, such ascold starting or running during the warmingup period. In Figure 1 themechanism for producing an enrichment in the mixture while the engine iscold is shown generally at 8 and consists of a casing |32 havingdisposed therein a bimetallic heat responsive element |34 including arms|35 and |36 hinged .on pin |31V in one end of casing |32.- Although inthe drawings a leaf type thermostat has been employed, it is understoodthat any equivalent heat responsive means, for example, a coiledbi-metallic element, may be substituted therefor, said elements beingconventional and often employed as control elements in internalcombustion engine fuel systems. Adjacent casing |32, though notnecessarily mounted thereon as shown in the drawings, is a control valveunit |38 consisting of a housing |39, a fuel chamber |40 and a gaschamber |42, said charnbers being separated by a fuel impermeableflexible diaphragm |44 secured in position by being marginally clampedbetweentwo halves of housing |39. Unmetered fuel from passage 42 enterschamber |40 through conduit |46 and is discharged into conduit |41through orifice |48, the effective size of which is controlled by poppetvalve |50 carried by a valve stem |52 and flexible diaphragm |44. Stem|54 is secured to the diaphragm'on the side opposite valve stem |52 andextends into casing |32 to engage arm |36 of the thermostat |34.Diaphragm |44 is constantly urged to the left as shown in the drawings,when the engine is operated, .by the pressure of the unmetered fuel inchamber |40 and thus tends to close valve |50 and to force arm |36 ofthe thermostat to the left. Thermostat |34 may be adjusted laterally incasing |32 to increase or decrease the force tending to open poppetvalve |50 by adjusting the position of screw |55. Casing |32 isconnected through conduit |56 with a source of heated air, for example,with a stove on the exhaust manifold, and through conduit |00 with theinduction passage. By this arrangement, air of a temperature variable inaccordance with that of the engine is drawn into casing |32 around thethermostat, which expands when cooled to force poppet valve |50 to itsopen position and contracts as shown in the drawings when heated topermit said valve to close. It can readily be seen that when the engineis cold, valve |60 is held open by the thermostat, permitting fuel toflow from the unmetered passage 42 into chamber 44 to increase thedischarge of fuel through orifice 41, conduit 60, distributor 62 anddischarge nozzle 68. Chamber |42 is vented through passage |58 to theair passages of the control unit, and consequently diaphragm |44 issubjected to the intake manifold or induction passage suction through`conduit |00. Restrictions |60 and |62 are provided in conduits |01* and|56 adjacent'casing |32 for limiting the air flow in the heated airpassages to prevent the suction in passage |00 from being dissipated toa point where it would be ineffective tc operate the control valve 84 oraccelerating unit |05 and to reduce the bleeding of air into the enginemanifold so as to avoid adversely aiecting the operation of the engine.

The throttle valve control assembly consists of a manually operatedlever |64 mounted on one end of throttle valve shaft |66, a conventionalfast idle cam shown at |68 provided with a plurality of steps, and astop screw |10 for engaging the fast idle cam inserted in arm |12 oflever |64 and held in the desired adjusted position by spring |14. Theposition of the several steps on cam |68 is determined by the positionof the thermostat |34 acting through rod |16 against an abutment on saidcam. A torsion spring, not shown,

may be used to lightly urge cam |68 in a clockwise direction, as shownin Figure 3. An extension of rod |16 having lug |11, and a pin |18 onlever |64, as shown in Figures 1 and 3, are provided to withdraw arm |36of thermostat |34 from stem |54 and permit valve |50 to close when thethrottle valve is wide open. The pin |18 on lever |64 does not engagelug |11 until tle throttle valve is wide open and overtravel of lever|64 is effected. The overtravel is permitted by a yieldable connectionconsisting of` a spring curved around shaft |66 and having one endanchored in said shaft and the other end secured to the throttle Valvelever |64. By this arrangement, in the event the engine becomes flooded,the inrush of air when the throttle valve is in wide open position andfuel valve |50 in closed position removes the excess fuel from theintake manifold and engine cylinders.

A cross section of one of the discharge nozzles together with a portionof the intake manifold 10 and discharge conduit`66 is shown in Figure 4in which are included an outlet passage 200 and an orifice 2 0?2controlled by valve 204 mounted on reciprocable stem 206 and urged toits closed position by a calibrated spring 208 reacting between bearing2|0 supporting stem 206 and collar 2|2 secured to stern l206 near theend thereof opposite valve 204. Valve 204 remains closed until thepressure in conduit 66 and passage 200 builds up Operation In the normaloperation of the present fuel metering device, fuel enters gear pump I0through inlet 20 and passage 2| and is delivered thereby through passage24 to impeller 88, the pressure of said fuel between thegear pump andimpeller being maintained at a substantially constant pressure by valve28 and a calibrated spring 34 in pump by-pass 28. The fuel delivered tothe impeller of the centrifugal pump 38 is discharged therefrom intopassage 42 at an increased pressure. The pressure of the fuel dischargedfrom the centrifugal pump will be greater than the pump inlet pressureby an amount which is directly proportional to the square of the speedof the impeller and thus directly proportional to the square of theengine speed.

The fuel from the impeller ows under in-v creased pressure throughmetering orifice 48 into chamber 44 wherein it urges diaphragm 52, valvestem U -and valve 48 from orifice 41 permitting the fuel of chamber 44to discharge into conduit 80. The fuel in conduit 6l) is deliveredintermittently by revolving Agroove 81 of the distributor to the severaldischarge conduits 88 and nozzles 68 disposed in intake manifold 18.

The discharge of fuel through orifice 41 is regulated by the variablepressure in chamber 12 and passage 80 which communicate through orifice82 with passage 24 anterior to the` impeller and through valvecontrolled orifice 86 with the unmetered fuel in passage 42, creating apressure in passage 80 and -chamber 12 whichwill be of a thedifferential between the pressure of the un-" metered fuel posterior tothe impeller and the pressure in passage 80 will vary as the square ofthe engine speed for any particular setting of the valve 84.

In the control unit, springs 14 and 18 are substantially in balance andare preferably so adjusted by screws 18 that valve 48 will close orifice41 when the engine is not operating, thus preventing the discharge offuel except when the engine is being cranked or operating under its ownpower. The pressures of the fuel, therefore, in chambers 44 and 12 willbe maintained substantially equal during the operation of the engine,inasmuch as any increase in pressure in chamber 44, however slight, willcause valve 48 to open wider and permit the fuel to discharge throughorifice 41 at a greater rate until the pressures in the two chambers areagain equal. Should the pressure in fuel chamber 12 increase, the forcethereof on diaphragm 52 will urge valve 48 toward its closed position,restricting the discharge of fuel through orifice 41, thus permittingthe pressure in chamber 44 to increase until it is equal to the newpressure in chamber 12. Since the pressure of the meteredfuel in chamber44 is fequal to control pressure in chamber 12 and the differentialbetween the pressure of the unmetered fuel in conduit 42 and the controlpressure varies as the square of the engine speed, the differentialbetween the pressure '.in chamber 44 and that of said unmetered fuellikewise varies as the square of the engine speed for a given setting ofvalve 84. From the following, it is apparent that variations in pressurein chamber 12 result in an increase or a decrease as the case may be inthe quantity of fuel discharged through metering orifice 48.

The quantity of fuel which will flow through a given size meteringorifice, such Aas metering orifice 48, will vary in proportion to thesquare root of the differential in the pressure between the fuel inpassage 42 and in chamber 44 on opposite sides'of said orifice, andsince this differential varies as the square of the engine speed, it isapparent that theY quantity of fuel which will flow through orifice 48for a given setting of valve 84 will vary directly as the engine speed.

Since the weight of air flow to an engine at a given manifold pressurevaries substantially in direct proportion to engine speed, the fuelmeterying device described herein will supply fuel to the engine inaccordance with air flow into the engine.

. If. the weight of air supplied the engine for any given speed shouldincrease by increase in manifold pressure, the quantity of fueldelivered thereto will be increased accordingly by the effect of theincreased pressure in the induction passage on diaphragm 81 urging valve84 toward its closed position. As valve 84 moves toward closed position,the pressure in the control conduit and chamber 12 is reduced as to morenearly approach the pressure in passage 24 anterior to the impeller, andas a consequence, valve 48 will open to permit fuel to discharge to theengine at a greater rate such that the pressure of the metered fuel inchamber 44 will be reduced to equal the reduced pressure in the controlpassage 80 and chamber 12. In othery words, reducing the pressure incontrol passage 80 and chamber 12 reduces the pressure in chamber 44 andthereby increases the differential between the pressure of the unmeteredfuel in passage 42 and the metered fuel in chamber 44. The fuel istherefore delivered through orifice 48 at a greater rate to com'-pensate for the increased weight of air entering the engine.

In the present metering device, the valve for regulating the controlpressure is adapted to operate to enrich the fuel mixture at high speedsto satisfy engine requirements. When the engine is idling, the pressureof the air in the manifold is relatively low, and as a result, theunmetered fuel pressure in chamber 81 and the atmospheric pressure inchamber 98 urge diaphragms 81 and 9| to the left and valve 84 to itsopen position, thereby increasing the effective area of orifice 86. Withthe valve in this position, the pressures in passage 80 and chamber 12are relatively high and, by acting on diaphragm 52 and valve 48, createan equally high pressure in chamber 44 and a low differential acrossmetering orifice 46, resulting in a low discharge of fuel through saidmetering orice to the engine as previously described. When the engine isoperating at relatively high speeds, Which normally require an enrichedfuel-to-air-mixture, the vacuum in induction passage will be relativelylow, and valve 84 will be urged toward its closed position, restrictingfuel in passage 42 and chamber 91 from entering passage 80. As a result,the pressure in v passage 80, chambers 12 and 44 will approach the lowerpressure in passage 24, causing an increase in the differential acrossorifice 48 and consequently an increase in the flow of fuel therethroughto the engine as previously mentioned.

It is well known that as the speed of an internal combustion engine isincreased, the volumetric eiciency thereof gradually decreasesthroughout most of the operating range, this decrease being particularlymanifest at relatively high speeds. Since the present metering devicedelivers fuel to the engine at a rate directly proportional to the speedof the engine and consequently to the theoretically maximum volumetriceiiiciency of the engine, the fuel-to-air ratio would, unless corrected,become richer as the volumetric emciency became less. To maintain thecorrect fuel-to-air ratio regardless of variations in volumetriceiiiciency, the present metering device includes small diaphragm 9|which forms one wall of chamber 91 and is thussubject to the pressure ofthe unmetered fuel posterior to the impeller. By this arrangement, saidunmetered fuel pressure, which varies as the square of the engine speed,urges diaphragm 9| Vand valve 84 to the left permitting the pressure incontrol passage 80 and chamber 12 to change at a slightly greater ratethan that effected by change in impeller speed. As previously explained,an increase in pressure in chamber 1-2 causes an equal increase inpressure in chamber 44 and a smaller differential across meteringorifice 46. The fuel discharged, therefore, is reduced to approximatelythe amount required to compensate for the decrease in volumetricefficiency.

In the acceleration of the engine,.the throttle valve is normally openedrapidly, resulting in a substantial decrease in the vacuum in theinduction passage and a corresponding increase in the weight of airentering the engine. At this point in the operation of the engine it isgenerally desirable to increase the ratio of fuel-to-air to give atemporary high power output to the engine. In the mechanism foraccomplishing this temporary enrichment, the increase' in pressure inthe induction passage which results when the throttle valve is opened istransmitted through conduit to chamber |20 and urges diaphragm ||'8 tothe left as Shown in Figure 1, thereby compressing spring |28 andconsequently decreasing the force tending to close valve |08. During theinterval of increased pressure in chamber |20, the pressure of theunmetered fuel in chamber |26 urges diaphragm ||'2 and valve |08 to theleft, opening said valve and permitting additional fuel to be deliveredto the distributor and thence to the engine. l the pressure in chamber|22 to gradually build up and to equalize the pressures in chambers |20Aand 22 so that the Ioriginal effective force of spring |28 tending toclose valve |08 is again obtained. The valve |08 then closes and remainsclosed until the pressure in the induction passage is again increased.

During starting and warming-up of the engine, a higher ratio offuel-to-air` is required than during normal operation of the engine. Inthe present fuel metering device, this higher fuel ratio is accomplishedby a thermostatically controlled valve |50 which admits fuel while theengine is cold from the unmetered fuel passage through conduit |46 toconduit |41 communicating with the metered fuel passage anterior tovalve 48, thus tending to increase the pressure in chamber 44 andconsequently the discharge of fuel through orifice 41. When the enginebecomes Warm, the heated air drawn through casing collapses thermostat|34 permitting the pressure on diaphragm |44 to close valve |50.-

The fast idle cam |68 which prevents the throttle valve from completelyclosing when the engine is lcold is regulated by the thermostat |34through rod |16 secured to arm |36 of the 10 thermostat, said rod beingadapted to rotate said cam in accordance with the position of said arm.The wide open kick arrangement which is adapted to close valve |50 whenovertravel of the throttle valve lever is effected permits the removalof excess fuel from the induction passage, intake manifold and cylinderswhen the engine has become flooded in starting.

A relatively small port |24 permits Figure 5 In the modification of thepresent invention shown in Figure 5, in which elements found in thepreceding gures retain their original numbers, the ratio of fuel-to-airis regulated in accordance with engine speed and temperature and withthe pressure in the induction passage as determined by the position ofthe throttle valve. In this arrangement, the position of valve 84, whichregulates the pressure in control passage 80, is coordinated with themovement of the throttle valve '6 by any suitable connecting mechanism.The mechanism shown in the Figure 5, which is included only for thepurpose of illustrating one possible connecting arrangement, consistsof. a rod 230, a centrally pivoted lever 232, a rod 234 and a lever 235pivotedat 236 and having a longitudinal slot 231 in'w'hich a pin 238seated in the throttle lever |64 is adapted to slide during thelmovement of the throttle valve 6. Shaft 230 is adapted to movelongitudinally in guide 239 and to engage the head of vpin 94 andindirectly valve stem 89 in order that valve 84l may be urged toward itsclosed position by the opening movement of the throttle valve 6, saidvalve 84 being urged toward its open position by the pressure of theunmetered fuel in chamber 91 urging diaphragm 9| and valve 84 totheleft. Lever 232 is provided with a cam 240 for engaging the free end ofshaft 230, said cam preferably being so contoured as to produce certaindesired fuel-to-air relationships for various engine operatingconditions. For example, the cam can be provided with a peripheral humpat the point contacting the end of shaft 230 when the throttle is wideopen, causing a relatively small opening through orifice 86 andconsequently an increase in the discharge of fuel to the engine toprovide a rich mixture while the engine is operating at high speed andpulling under heavy load.

Rod 234 which connects the end of lever 232 opposite the cam end withlever 235 is provided with nuts 242 and 244 on either side of lever 232to permit adjustment of said levers relativeV to one another. it is seenthat the construction and operation of the fuel metering device shown inFigure 5 are similar Ain most respects to those of the device shown inthe precedinggures, the only variations in construction and operationbetween the two embodiments being those mentioned in the description ofFigure 5.

Although only two specific examples of our invention have been includedin the description, it will be understood that many variations may bemade without departing from the scope of the invention. It iscontemplwted that other elements or devices than those shown in thedrawing may be included in th'e present metering device to obtainsatisfactory fuel-to-airmixtures under all engine operating conditions.A mechanism responsive to variations in atmospheric pressure may beincluded in the present meteringdevice for varying the fuel-to-air ratioto maintain proper charging mixtures under substantial variations inatmospheric pressure. A superchargermay also be included in the airintake passage disposed either anterior or posterior to the throttlevalve. The modifications necessary to include the foregoing elements inthe present device will be apparent to those skilled in the art.

We claim:

1. In a fuel supply system for an engine, a fuel supply conduit, a meansfor varying the pressure of the fuel in said conduit in accordance withengine speed, a passageway communicating with said conduit on eitherside of said pressure varying means and having two calibrated orificestherein, ameans for varying the effective sizeV of one of said orifices,a metering jet disposed in said conduit downstream from said passageway,a valve'in said conduit posterior to said metering jet regulated by thepressure in said passageway between said orifices, a plurality of fueldischarge means communicating with said valve for delivering meteredfuel to the air entering the engine, and a temperature responsive meansfor controlling the richness of the fuel-to-air mixture.

2. In a fuel supply system for an engine having an induction passage, aconduit for delivering fuel to said induction passage, a means forvarying the pressure of the fuel in said conduit in accordance withengine speed, a passageway communicating with said conduit on eitherside of said pressure varying means and having two' means forcontrolling the richness of the fuelto-air mixture in accordance withengine t'emperature.

3. In a fuel supply system for an engine having an induction passage, aconduit for delivering fuel to said induction passage, a means forvarying the pressure of the fuel in said conduit in accordance withengine speed, a passageway cornmunicating with said conduit on the inletand outlet sides of said pressure varying means and having twocalibrated orifices therein, a' means for varying the effective size ofthe orifice adjacent said outlet side in response to pressure changes insaid induction passage thereby creating a variable pressure in saidpassageway, a metering jet disposed in said conduit downstream from saidpassageway, a valve in said conduit posterior to said metering jetregulated by the variable pressure in said passageway between saidorices, a plurality of fuel discharge means communicating with saidvalve for discharging metered fuel intermittently into said inductionpassage and a temperature responsive means for controlling the richnessof the fuel-to-air mixture in accordance with engine temperature.

4. In a fuel supply system for an engine having an induction passagewith a throttle valve therein, a conduit for delivering fuel to saidinduction passage, means foi` varying the pressure of said fuel in theconduit in accordance with engine speed, a passageway communicating withsaid conduit on either side of said pressure varying means and havingtwo calibrated orifices therein, means for varying the effective size ofone of said orifices with variations inthe pressure in said inductionpassage accompanying change in throttle position thereby creating avariable pressure in said passageway, a metering jet disposed in saidconduit downstream from said passageway, a valve in said conduitposterior to said metering jet regulated by the variable pressure insaid passageway between said orifices, a plurality of fuel dischargenozzles communicating with said valve for delivering metered fuel to theinduction passage posterior to said throttle Valve, a fuel distributorbetween said nozzles and said valve for synchronizing the discharge offuel with the firing of the cylindersadjacent the respective nozzles,and a temperature responsive means for controlling the richness of thefuel-toair mixture in accordance with engine temperature.

5. In a fuel supply system for an engine having an induction passagewith a throttle valve therein, a conduit for delivering fuel to saidinduction passage, means-for varying the pressure of said fuel in theconduit in accordance with engine speed, a passageway communicating withsaid conduit on either side of said pressure varying means and havingtwo calibrated orifices therein, means for varying the effective size ofone of said orifices in response to pressure changes in said inductionpassage thereby creating a variable pressure in said passageway, ametering jet disposed in said conduit downstream from said passageway, avalve in said conduit posterior to said metering jet regulated by thevariable pressure in said passageway between said orifices, a pluralityof fuel discharge nozzles communicating with said Valve for deliveringmetered fuel to the induction passage posterior to said throttle valve,a fuel distributor between said nozzles and said valve for synchronizingthe discharge of fuel with the firing of the cylinders adjacent therespective nozzles, a temperature responsive means for controlling therichness of the fuel-toair mixture in accordance with enginetemperature, and a means controlled by the pressurefin the inductionpassage for causing temporary enrichment in the fuel-to-air mixture whensaid throttle valve is opened.

6. In a fuel supply system for an engine having an induction passagewith a throttle valve therein, a conduit for delivering fuel to saidinduction passage, a means for varying the pressure of the fuel in saidconduit in accordance with engine speed, a passageway communicating withsaid conduit on either side of said pressure varying means and havingtwo calibrated orifices therein, means actuated by the movement of saidthrottle valve for varying the effective size of one of said orifices, ametering jet disposed in saidv conduit downstream from said passageway,a valve in said conduit posterior to said metering jet regulated by thepressure in said passageway between said orifices, a plurality of fueldischarge means communicating with said valve for discharging meteredfuel intermittently into said induction passage, and a temperatureresponsive means for controlling the richness of the fueltc-air mixturein accordance with engine temperature.

'7. In a fuel supply system for an engine having an induction passagewith a throttle valve therein, a conduit for delivering fuel to saidinduction passage, means for varying the pressure of said 75 fuel in theconduit in accordance with engine of said orifices thereby creating avariable pres-4.

sure in vsaid passageway, a metering jet disposed in said conduitdownstream from said passageway, a valve in said conduit posterior tosaid metering jet regulated by the variable pressure in said passagewaybetween said orices, a plurality of fuel discharge nozzles communicatingwith said valve for delivering metered fuel to .the induction passageposterior to said throttle valve, a fuel-distributorbetween said nozzlesand said valve for synchronizing the discharge of fuel with the firingof the cylinders adjacent the respective nozzles, and a temperatureresponsive means for controlling the richness of the fuel-to-air mixturein accordance with engine temperature.

8. In a fuel supply system for an engine, a fuel supply conduit, a meansfor varying the pressure of the fuel in said conduit in accordance withengine speed, a means for delivering fuel from a source to said pressurevarying means, a

passageway communicating with said conduit on eitherv side of saidpressure varying means and having two calibrated orifices therein, a,means for varying the effective size of one of said orifices, a meteringjet disposed in said conduit downstream from said passageway, a valve insaid' conduit posterior to said metering jet regulated bythe pressure insaid passageway between said orifices, a plurality of fuel dischargemeans communicating with said valve for delivering metered fuel to theair entering the engine, and a temperature responsive means forcontrolling the richness of the fuel-to-air mixture.

9. In a fuel supply system for an engine having an induction passage, aconduit for delivering fuel to said induction passage, means for varyingthe pressure of the fuel in said conduit in accordance with enginespeed, a means for delivering fuel from a source to said pressurevarying means, a passageway communicating with said conduit on eitherside of said pressure varying means and having two calibrated orificestherein, a means for varying the effective size of one of said orificesin response to the pressure changes in said induction passage, ametering jet disposed in said conduit downstream from said passageway, avalve in said conduit posterior to said metering jet regulated by thevariable pressure in said passageway between said orifices, a pluralityof fuel discharge means communicating with said valve for deliveringmetered fuel to the air entering the engine, a fuel distributor in saidconduit between said valve and said discharge means yfor -synchronizingthe discharge of fuel with the firing of the cylinders adjacent to therespective nozzles, a temperature responsive means for controlling therichness of the fuel-toair mixture in accordance with enginetemperature, and a means controlled by the pressure of air in theinduction passagefor causing temporary enrichment in the fuel-to-airmixture when the throttle valve is opened.

10. In a device for supplying fuel to an engine under superatmosphericpressure, said engine having an induction passage, a conduit, a meansdriven by said engine for varying the pressure of the fuel in theconduit by an amount proportional to the square of the engine speed, a

means for supplying fuel from a source to said stant pressure, apassageway communicating with said conduit on the inlet and outlet sidesof said pressure varying means and having two calibrated orificestherein, a means for varying the effective size of the orifice adjacentthe outlet side of said pressure varying means in response to pressurechanges in the induction passaga'a metering jet -entering the engine, afuel distributor between said discharge means and said valve forsynchronizing the discharge fuelnwith the firing.

of cylinders adjacent the respective nozzles, a temperature responsivemeans for controlling the richness of the fuel-to-air mixture inaccordance with engine temperature, and a means controlled by thepressure inthe induction passage for causing temporary enrichment of the`fuelto-air mixture when the throttle valve is opened.

11. In a fuel supply system for an engine having an induction passagewith a throttle valve therein, a fuel supply conduit, a means forvarying the pressure of the fuel in said conduit in accordance with theengine speed, a means for delivering fuel from a source to said pressurevarying means, a passageway communicating with said conduit on eitherside of said pressure varying means and having two calibrated orificestherein, a means actuated by the movement -of said throttle valve forvarying the effective size of one of said orifices, a metering jetdisposed in said conduit downstream from said passageway, a valve insaid conduit posterior lto said metering jet regulated by the pressurein said passageway between said orifices, a plurality of fuel dischargemeans communicating with said induction passage, a distributor fordelivering metered fuel intermittently from said valve to the severaldischarge means, and. a temperature responsive means for controlling therichness of the fuel-toair mixture.

12. In a fuel supply system foran engine having an induction passage, aconduit for delivering fuel to said induction passage, a means forvarying the pressure of the fuel in said conduit in accordance withengine speed, a passageway communicating with said conduit on eitherside of said pressure varying means and having two calibrated orificestherein, means for varying the effective size of one of said orifices inresponse to the pressure changes in said induction passage, meansresponsive to the pressure variations produced by the first mentionedmeans for correcting for variations in volumetric efficiency of theengine, a metering jet disposed in said conduit downstream from saidpassageway, a valve in said conduit posterior to said metering jetregulated by the pressure in said passageway between said orifices, aplurality of fuel discharge means communicating with said valve fordischarging metered fuel intermittently into said induction passage, anda temperature responsive means for controlling the richness of thefuel-to-air mixture in accordance with engine temperature.

13. In a vfuel supply system for an engine having an induction passage,a conduit for delivering fuel to said induction passage, a means forvarying the pressure of the fuel in said conduit in accordance withengine speed, a` passageway' communicating with said conduit on eitherside pressure varying means at a substantially con- 76 of said pressurevarying means and having two 15 calibrated orifices therein, means forvarying the effective size of one of said orifices in response to thepressure changes in said induction passage, means responsive to thepressure variations produced by the firs-t mentioned means .forcorrecting for variations in volumetric eiliciency of the engine, ametering jet disposed in said conduit downstream from said passageway,

a valve in said conduit posterior to said metering jet regulated by thepressure in said passageway between said orifices, and a plurality offuel discharge means communicating with said valve for dischargingmetered fuel intermittently into said induction passage.

14. In a fuel supply system for an engine having an induction passagewith a throttle valve therein, a conduit for delivering fuel to saidinduction passage, means for varying the pressure of said fuel in theconduit in accordance with engine speed, a passageway communicating withsaid conduit on either side of said pressure varying means and havingtwo calibrated orifices therein, means for varying the effective size ofone of said orifices in response to pressure changes in said inductionpassage thereby creating a variable pressure in said passageway, ametering jet disposed in said conduit downstream from said passageway, avalve in said conduit posterior to said metering jet regulated by thevariable pressure in said passageway between said orifices, a pluralityof fuel discharge nozzles communicating with said valve for deliveringmetered fuel to the induction passage posterior to said throttle valve.a fuel distributor between said nozzles and said valve for synchronizingthe discharge of fuel with the firing of the cylinders adjacent therespective nozzles, a temperature responsive means for controlling therichness of the fuel-to-air mixture in accordance with enginetemperature, and a means controlled by said temperature responsive meansfor preventing said throttle valve from completely closing when theengine is cold.

15. In a device for supplying fuel to an engine under superatmosphericpressure, said engine having an induction passage with a throttle valvedisposed therein, a conduit for delivering fuel to said inductionpassage, a centrifugal pump driven by said engine for varying thepressure i fuel in the conduit by an amount substantially proportionalto the square of the engine speed, l

a gear pump fordeliveringfuel from a source to said centrifugal pump ata substantially constant pressure, a passageway communicating with saidconduit on the inlet and outlet sides of said centrifugal pump, andhaving two calibrated oriflces therein, a valve for varying theeffective size of the orifice adjacent the outlet side of thecentrifugal pump in response to the changes in pressure in the inductionpassage, a metering jet disposed in the conduit downstream from saidpassageway, a valve in said conduit posterior to the metering jetregulated by the pressure in said passageway between said orifices, aplurality of discharge nozzles disposed in said induction passage andcommunicating with the second mentioned valve, a fuel distributorbetween said nozzles and said second mentioned valve for synchronizingthe discharge of fuel with the firing of the cylinders adjacent therespective nozzles, a thermostat, a valve controlled by said thermostatfor controlling the richness of the fuel-to-air mixture in accordancewith engine temperature,

of the fuel in said conduit by an amount substantially proportional tothe square of the engine speed, a passageway communicating with saidconduit on the inlet and outlet sides of said centrifugal pump andhaving two calibrated orifices therein in spaced relation to oneanother,

a valve for varying the effective size of the orifice adjacent theoutlet side of said pump in response to the changes in pressure in theinduction passage, a metering jet disposed in said conduit downstreamfrom said passageway, a valve in said conduit posterior to said meteringjet regulated by the pressure in said passageway between said and a fastidle cam, the position of which is controlled by said thermostatv forpreventing said throttle valve from completely closing when the engineis cold.

17. For use in a fuel supply system of an engine, a disc adapted to berotatably driven by the engine, impeller blades on one side of the discfor receiving fuel from a source and delivering it to a fuel meteringunit under an increased pressure, a radial slot on the other sidel ofsaid disc adapted to receive fuel at its central portion from the fuelmetering unit and to deliver it to a plurality of nozzles inintermittent communication with I the outer portion of said slot.

18. For use in a fuel supply system for an engine, the combination of acentrifugal pump and a fuel distributor comprising a disc-like memberadapted to be rotatably driven by the engine, impeller blades on oneside of the disc for creating a fuel pressure variable with enginespeed, and a radial slot on the other side of the -disc for receivingmetered fuel and delivering it intermittently to a plurality of conduitsin timed relation with the engine.

19. In a fuel supply system for an engine having an induction passage, aconduit for delivering fuel to the engine, a means for varying thepressure of the fuel in said conduit in accordance with engine speed, apassageway communicating with said conduit on either side of saidpressure varying means and having two calibrated orifices therein, meansfor varying the effective size of one of said orifices with change in acondition selected from tl1e group consisting of throttle position andinduction passage pressure, a metering jet in said conduit downstreamfrom said passageway, a valve in said conduit posterior to said meteringjet, a movable wall connected to said valve and urged in valve closingdirection by a pressure varying with the pressure in said passagewaybetween said orifices and in a valve opening direction by a pressurevarying with the pressure in said conduit between the valve and 17metering jet, a plurality of fuel discharge means communicating Withsaid valve for delivering fuel to said engine, and a means adapted torespond to an engine variant for varying the fuel delivery obtained bythe remainder of said supply system.

20. For use in a fuel system of an engine, the combination of acentrifugal pump, a fuel distributor and a fuel supply pump, comprisinga casing, a stator having at least one rotatable pump member thereinmounted on a rotatable shaft, said shaft adapted to be driven by saidengine, a second stator having an impeller thcrein, a fuel distributorhaving a radial slot for delivering fuel to a plurality of conduitscommunieating with said engine, a drive connecting said rotatable pumpmember and said impeller and a second drive connecting said impeller andsaid distributor whereby said rotatable member, impeller and distributorare driven together.

21. For use in a fuel system of an engine, the combination of acentrifugal pump and a fuel supply pump, said combination comprising acasing, a stator having at least one rotatable pump member thereinmounted on a rotatable shaft, said shaft being adapted to be driven bysaid engine, a second stator having an impeller therein adapted toreceive fuel from said fuel supply pump and to discharge the fuel at anincreased pressure, and a drive connecting said rotatable pump memberand said impeller whereby said rotatable member and impeller aredriventogether and a fuel pressure regulating means between said pumps.

22. In combination with an engine fuel system adapted to supply fuel atsuperatmospheric pressure to an induction passage of said engine, aconduit for delivering fuel to said induction passage, a pump means forvarying the pressure in said conduit by an amount substantiallyproportional to the square of the engine speed, and a pump for receivingfuel from a source and for delivering it to said pressure varying meansat a subf stantially constant pressure, the operation of said pressurevarying means and said pump being synchronized.

23. In a fuel supply system for an engine having an induction passage,aconduit for delivering fuel to said induction passage, a means forvarying the pressure of the fuel in said conduit in accordance withengine speed, a passageway communicating with said conduit on the inletand outlet sides of said pressure varying means and having twocalibrated orifices therein, means for varying the effective size of oneof said orifices upon change in manifold pressure resulting from changein throttle position, a metering jet disposed in said conduit downstreamfrom said passageway, a valve in said conduit posterior to said meteringjet regulated by the variable pressure in said passageway between saidorifices, a plurality of fuel discharge means communicating withsaidvalve for discharging metered fuel intermittently into said inductionpassage and a temperature responsive means for controlling the richnessof the fuel-to-air mixture in accordance with engine temperature.

24. In a fuel supply system for an engine, a

fuel supplyY conduit, a means for varyingv the pressure of the fuelinsaid conduit in accordance with engine speed, a passagewaycommunicating with said conduit on either side of said pressure varyingmeans and having two calibrated orifices therein,l means responsive tochange in load for varying the size of one of said orifices, a meteringjet disposed in said conduit downstream from said passageway, a valve insaid conduit posterior to said metering jet regulated by the pressure insaid passageway between said orifices, a plurality of fuel dischargemeans communicating with said valve for delivering metered fuel to theair entering the engine, and a temperature responsive means forcontrolling the richness of th'e fuel-toair mixture.

25. In a fuel supply system for an engine hav- `ing an induction passageWith a throttle valve therein, a conduit for delivering fuel to saidinduction passage, a means for varying the pressure of the fuel in saidconduit in accordance with engine speed, a passageway communicating withsaid conduit on either side of said pressure varying means and havingtwo calibrated orifices therein, means for varying they effective sizeof one of said orifices upon variations in load resulting fromvariations in throttle position, a metering jet disposed in said conduitdownstream from said passageway, a valve in said conduit posterior tosaid metering jet regulated by the pressure in said passageway betweensaid orices, a plurality of fuel discharge means communicating with saidvalve for discharging metered fuel intermittently into said inductionpassage, and a temperature responsive means for controlling the richnessof. the 'fuel-to-air mixture in accordance with engine temperature,

26. In a fuelsupply system for an engine hav- \ing an induction passage,a conduit for delivering fuel to said induction passage, a means forvarying the pressure of the fuel in said conduit in accordance withengine speed, a passageway communicating with said conduit on eitherside of said pressure varying means and having two calibrated orificestherein, means for varying the effective size of one of said orifices inresponse to the changes in pressure in said induction passage, meansresponsive to the pressure variations produced by the first mentionedmeans for correcting for variations in volumetric eiiiciency, a meteringjet disposed in said conduit downstream from said passageway, and avalve in said conduit posterior to said metering jet regulated by thepressure in said passageway between said orifices.

EMIL O. WIRTH. FREDERIK BARFOD.

REFERENCES CITED Tie following references are of record in the file ofthis patent:

UNITED STATES PATENTS

